A large percentage of the world population are infected with herpes viruses. Three of the most common herpes viruses are herpes simplex virus-1 (HSV-1) which is the cause of facial and ocular sores, herpes simplex virus-2 (HSV-2) which has a predilection for genital areas, and herpes simplex virus-3 (HSV-3), also named herpes zoster and varicella zoster, which causes chicken pox and later shingles. Human herpes virus-8 is associated with the skin cancer Kaposi sarcoma. These herpes episodes are each susceptable to topical treatments because the viruses replicate in subdermal cells during a recurrence leading to an eruption into a lesion. Inhibition of viral fusion with or entry into a host cell is a treatment method disclosed here versus herpes viruses using a mixture of long chain monounsaturated alcohols represented by jojoba alcohol as the inhibitor. Examples of transdermal delivery of drugs are also described. More than 275 unique chemical compounds and compositions have been reported as skin penetration enhancers for transdermal drug delivery (Osborne and Henke, www.pharmtech.com/technical/osborne/osborne/htm).
Once an individual is infected, herpes viruses become latent principally in nerve cells, and can reactivate to cause recurrences of the original symptoms. When a herpes virus infected individual undergoes stress from exhaustion, strong sunlight, wind, certain foods and medications, menses or microbial infection, the virus migrates to vascular cells under the epidermis where it begins to replicate. For HSV-1 and HSV-2 the initial itchiness, tingling or pain is referred to as the prodromal stage signaling that the virus is active under the skin. Prodromal can occur from an hour to several days before an outbreak of lesions. At the erythema or inflammation stage, the immune system has begun to fight the virus. After this irritating redness stage, vesicles form and eventually erupt into lesions on the skin and mucosal surfaces. HSV-1 and HSV-2 are morphologically indistinguishable, the main difference being where the sores appear on the skin, and there is some interchange in recurrence sites between these two viruses. Herpes migration to the brain or spinal cord leads to encephalitis and meningitis, which are life-threatening conditions.
There are several treatment options for herpes infections but no cures. Several of the nucleoside analog drugs can be effective if taken prophylactically on a daily basis. They are less effective if administered at the time of the recurrence, either orally or topically. The nucleoside drugs inhibit viral replication by penetrating into the cell and interfering with nucleic acid production. They are not virucidal, and depend on a functional immune system to deactivate any virus present. A number of commercial “cold sore” preparations are available which treat symptoms, but are generally ineffective in preventing the formation of lesions. They contain principally anesthetic, antibacterial, emolient and wound healing compounds which can reduce pain, prevent microbial infection and help dry up the blister. Topical treatments of herpes simplex virus infections have been reviewed (Hamuy and Berman, Europ. J. Dermatol., 8:310-319, 1998; Evans and Tyring, Dermatol Clinic, 16: 409-419, 1998; Syed et al., Clin Drug Invest., 16: 187-191, 1998).
Alcohols with chain lengths of 16 to 20 carbon atoms and 1 to 4 double bonds inhibited herpes simplex and another lipid enveloped viral bacteriophage in cell cultures (Sands et al., Antimicrob. Agents Chemother., 15: 67-73, 1979). These unsaturated alcohols were more potent in vitro than saturated alcohols with shorter chain lengths (Snipes et al., Antimicrob. Agents Chemother., 11: 98-104, 1977). A patent (Rivici et al., U.S. Pat. No. 4,513,008, 1985) describes the inhibition of enveloped viruses such as herpes with linear polyunsaturated acids, aldehydes or primary alcohols with chain lengths of 20 to 24 carbons and 5 to 7 double bonds. These reports were followed by the investigations and development of n-docosanol as a topical treatment for herpes infections.
n-Docosanol, also named 1-docosanol and behenyl alcohol, is a straight chain 22 carbon saturated alcohol, which occurs in the bark, flowers and fruit of the tree Pygeum africanum. n-Docosanol is reported to have broad activity in cell cultures against lipid enveloped viruses such as herpes (Katz et al., Proc. Nat. Acad. Sci., 88:10825-10829, 1991; Katz et al., Ann. N.Y.Acad. Sci., 724: 472-488, 1994; Pope et al., J. Lipid Res., 37: 2167-2178, 1996; Pope et al., Antiviral Res., 40:85-94, 1998), and also the human inmmunodeficiency virus HIV (Marcelletti et al., AIDS Research and Human Retroviruses, 12: 71-74, 1996). These studies demonstrated that the antiviral activity of n-docosanol includes inhibition of the process of viral entry into the cell, while being mediated by intracellular metabolic biotransformation of the drug. A series of patents on the composition of mixtures of n-docosanol in formulations that render it useful for topical application supports these published reports (Katz, U.S. Pat. No. 4,874,794, 1989; Katz, U.S. Pat. No. 5,071,879, 1991; Katz, U.S. Pat. No. 5,166,219, 1992; Katz, U.S. Pat. No. 5,194,451, 1993; Katz, U.S. Pat. No. 5,534,554, 1996). n-Docosanol is not virucidal deactivating viruses directly, but it interferes with viral replication, and depends on a functional immune system to destroy herpes viruses. n-Docosanol is a crystalline waxy solid insoluble in water which needs to be formulated with a non-ionic surfactant and carrier to facilitate dermal penetration and interaction at the target cell level. This limitation was also noted where several other long chain compounds with 18 plus linear carbons including amides, alkanes, acids and alcohols needed to be formulated with a surfactant and carrier to facilitate penetration of the epidermis (Katz et al., U.S. Pat. No. 5,534,554, 1996; Katz et al., PCT WO98/11887, 1998; Katz et al., U.S. Pat. No. 5,952,392, 1999). The latter patents claim a composition of n-docosanol or other long chain compounds with a surfactant and a pharmaceutically acceptable diluent or carrier as the active viral replication inhibitor, rather than the pure individual compounds. The solid long chain alcohols and other compounds are not be expected to penetrate skin layers alone without a carrier. In a study using 10% n-docosanol suspended in an aqueous system containing a non-ionic surfactant and a carrier, mean healing time of lesions in humans infected with herpes labialis (HSV-1) was shortened (Habbema et al., Acta Derm. Venereol., 76: 479-481, 1996). A 12% n-docosanol cream was tested as a possible transmision prophylactic of simian immunodefficiency virus (SIV) in rhesus macque monkeys (Miller et al., Antiviral Res., 26: A277, 1995). Intravaginal application before exposure prevented transmission in five of the six monkeys tested. n-Docosanol and other saturated alcohols with chain lengths of 20 to 26 carbons reportedly promote corneal healing due to eye injury (Muller, U.S. Pat. No. 5,214,071, 1993; Muller, U.S. Pat. No. 5,296,514, 1994).
Jojoba oil, obtained from the seeds of the desert shrub Simmonsia chinensis, is a mixture of mono esters composed principally of both long chain monounsaturated alcohols and carboxylic acids (Miwa and Spencer, Proc. Second Int. Conf. on Jojoba and Uses, Ensenada, Baja Calif., Mexico, 229-243, 1976). Jojoba oil has been available commercially for more than twenty years, and several million pounds are used in cosmetic formulations annually. A significant characteristic of jojoba oil is its ability to be absorbed quickly by the ski This ready absorption has been related to the single carbon—carbon double bond occurring in the interior of both the alcohol and carboxylic acid parts of the mono ester molecules. Extensive testing and use of jojoba oil has established that it is completely safe when applied to human skin, or administered orally to mice, rats, marmots and rabbits (Taguchi and Kunimoto, Cosmetics and Toiletries, 92: 53-61, 1977; Clark and Yermanos, Biochem. Biophys. Res. Commun., 102: 1409, 1981; Hamm, J. Food Sci., 49: 417-428, 1984; Verschuren and Nugteren, Food Chem. Toxicol., 27: 45-48, 1989). Humans who have ingested jojoba seeds, which are 50% oil, have not been harmed, although some nausea occurred when as much as 200 grams were eaten. In mice, jojoba oil has functioned as an intestinal lubricant (Verbiscar et al., J.Agric. Food Chem., 28: 571-578, 1980). It is estimated that about 20% of jojoba oil is split by hydrolytic enzymes in the gastrointestinal system, thus producing jojoba alcohol in situ. After dermal absorption, jojoba oil is at least partially metabolized to jojoba alcohol. Jojoba oil is a generally recognized as safe product for cosmetic uses throughout the world.
Jojoba alcohol has been prepared from jojoba oil by hydrogenolysis with sodium and alcohol (Molaison et al, J. Amer. Oil Chem. Soc., 36: 379-382, 1959). An improved hydrogenolysis of jojoba oil has been reported (Verbiscar, U.S. divisional patent application, Feb. 12, 2001).
In these hydrogenolysis reactions, the carboxylic acid part of the ester is converted to its corresponding alcohol, in contrast to chemical hydrolysis where the fatty acids remain intact and must be separated from the alcohols in the mixture. Hydrogenolysis doubles the amount of jojoba alcohol that can be obtained from jojoba oil. One jojoba alcohol product prepared by hydrogenolysis was reportedly a mixture of octadec-9-enol, eiocos-11-enol, docos-13-enol and tetracos-15-enol (Taguchi, Proc. Sixth Int. Conf. Jojoba and Its Uses, eds. Wisniak and Zabicki, Ben-Gurian Univ. Negev, Beer-Shiva, Israel, p 371-391, 1984). The actual alcohol composition will vary according to the source of jojoba oil used in the hydrogenolysis. The relative amounts of individual alcohol components in jojoba alcohol depends on the ester composition of jojoba oil , a product obtained from seeds harvested in the Southwestern United States, Mexico, Israel and South America (Miwa, Spencer and Plattner, Proc. Second Int. Conf. Jojoba and Uses, Ensenada, Baja Calif., Mexico, 187-197, 1976). Plant variety, pollination, soil, climate and other cultural conditions will cause the chemical composition of jojoba oil, and thus jojoba alcohol, to vary. There is no single combination of alcohols, nor a percent range, that defines jojoba alcohol. Mixtures of monounsaturated alcohols can also be prepared from other sources, such as by the hydrogenolysis of sperm whale oil, a monoester similar to jojoba oil, or even from some plant triglycerides. In addition, a mixture of the alcohol components can be prepared by combining each individual alcohol in any specific amount. A formulated mixture of individual long chain alcohols will act like jojoba alcohol. Jojoba alcohol can actually be comprised of a number of individual principally long chain monounsaturated alcohols depending on the source of the seeds from which jojoba oil is derived. Jojoba alcohol is used here as a generic term representing mixtures of these alcohols which will remain liquiefied at ambient temperatures above about three degrees centigrade.
Pure long straight chain monounsaturated alcohols are waxy liquids or low melting solids, but when in a mixture as in jojoba alcohol exist as a colorless odorless oil at normal ambient temperatures. A characteristic of jojoba alcohol is that it is readily absorbed by human skin and does not require a carrier or surfactant to facilitate transdermal penetration. Jojoba alcohol is reported as a lipstick component along with a large number and variety of carboxylic acids, esters and alcohols with diverse structures and functions (Sato, Lipocolor Composition, U.S. Pat. No. 5,700,453, 1997). It is mentioned as an excipient in a formula with kojic acid (Honda, U.S. Pat. No. 5,750,563, 1998). The use of jojoba alcohol or any mixture of long chain monounsaturated alcohols as a skin penetration enhancer is new, unique and not previously known among such compositions (Osborne and Henke, ibid). Koey Perfumery Co., Tokyo, a company that introduced jojoba oil commercially as a cosmetic ingredient, also investigated the the safety of jojoba alcohol for cosmetic uses (Taguchi, 1984 ibid). The following mouse, rabbit, marmot and human tests were made for jojoba alcohol confirming that this product is very safe for topical application. Mutagenicity tests were also negative.
Acute Oral Toxicity In Mice Sixty inbred mice, 30 each male and female, separated into three groups, were fed jojoba alcohol with a stomach tube in a single dose. The first group received 32 ml/kg (27 g/kg), the second 40 ml/kg (34 g/kg), and the third group received 50 ml/kg (42.5g/kg). There were no deaths in any group after 7 days, so the oral LD50 value is above 50 ml/kg. The average weight dropped on day 1 but increased normally thereafter. Jojoba alcohol probably acts as an intestinal lubricant similar to jojoba oil, causing a weight change in the first 24 hours due to elimination of nutrients along with the jojoba alcohol in feces. There were no observed anatomical changes. Jojoba alcohol was not orally toxic to mice at these dose levels.
Ocular and Dermal Rabbit Tests Jojoba alcohol was dissolved in jojoba oil at three concentration levels of 50%, 25% and 12.5% on a w/w basis. The rabbits, three per dose level group, were administered 0.05 ml (1 drop) of these solutions in the right eye. The left eye was not treated. Eye irritation was very low with no effects on the cornea and iris, and mild conjunctivitis clearing up within 24-48 hours. In another test, ten male albino rabbits were treated with cloth strip patches on the skin with each of these three samples. Patches were removed from 5 rabbits after 15 days and from the remaining 5 rabbits after 30 days. Visual and pathological examination of the treated skin areas indicated that irritation was quite low and comparable among the three samples.
Dermal and Subcutaneous Marmot Tests Jojoba alcohol was dissolved in high purity jojoba oil at a 10% concentration. Albino marmots, 10 males and 10 females, were treated with this sample in a patch test. There was no sign of any irritation after 24 and 48 hours. In another test, the 10% solution of jojoba alcohol in jojoba oil was injected subcutaneously into 10 each male and female marmots. After 24 and 48 hours there was no evidence of irritation at the injection site. After one week the jojoba alcohol solution was spread on a cloth patch, and the patch was placed on the injection site. After two weeks a jojoba alcohol solution sample patch was placed on a challenge site away from the site of injection. No sensitization was observed at any of the sites.
Dermal Patch Human Tests A test was carried out on 40 humans with healthy skin. Two samples including 100% jojoba alcohol and 10% jojoba alcohol in jojoba oil were prepared on cloth strip patches. The patches were applied on the upper part of the back of 20 subjects for each sample. Results were observed after 30 minutes and after 24 hours. No evidence of irritation of any kind was observed in 39 of the subjects, and only one of the subjects on the 10% formula showed a possible reaction. A second test was carried out on another 40 subjects with contact dermatitis using pure jojoba alcohol on cloth strips patches. Only one of the test subjects showed a doubtful reaction in the first 30 minutes, and there were no positives after 24 hours. Jojoba alcohol is dermally non-toxic.